Light switch units for controlling the exterior lights of motor vehicles are frequently embodied as rotary switches. Such a rotary switch can be actuated to select from available modes of the exterior lights, for example the modes “OFF”, “headlight ON”, “parking light”, “side light”, and “automatic” or “AUTO.” An “AUTO” mode refers to the vehicle lights being automatically switched on and off as a function of the ambient brightness.
The rotary switch is typically latched or locked mechanically in the respectively selected position. However, in practice this can lead to the exterior lights remaining unintentionally switched on after the vehicle is exited. Furthermore, a situation can occur in which the headlights are not switched on in situations in which they are required or remain unnecessarily switched on in other situations. Such situations may occur, in particular, in vehicles with LED daytime running light with a comparatively high light output, in which situations the driver is possibly given the impression, owing to the LEDs, that the dipped headlight is switched on.
Future Economic Commission for Europe (ECE) automobile regulatory standards may require automatic switching on and off of the vehicle headlights as a function of the current ambient brightness conditions. Furthermore, at any time manual activation or deactivation must be possible, for example, in situations in which the light sensor is not functionally capable. In this context, the problem occurs that in the case of a switch with respectively latched or locked switching positions there is no possibility of activating the vehicle headlights independently of the respectively selected light switch position. If, for example, the auto light is selected, it is difficult for the user to understand how the vehicle headlight can be switched off.
The scenarios described above either result in reduced vehicle availability (owing to a discharged battery), increased safety risks, increased fuel consumption, increased CO2 emissions or failure to comply with future regulatory requirements.
DE 10 2009 000 536 A1 discloses a modular light switch unit for controlling lighting groups for a motor vehicle, in which light switch unit all the operator controls are embodied as pushbutton keys, wherein a main pushbutton key for switching the headlight on and off, which is enlarged compared to the other pushbutton keys, is surrounded by the other relatively small pushbutton keys. Using such pushbutton keys, which in contrast to conventional rotary, rocking or latching keys do not latch in a position which predefines an operating position of the assigned lighting mode, is intended to ensure that, for example when switching on the ignition of the motor vehicle, the control is operated in the “auto light” mode with the side light or headlight switched on as a function of the ambient light.
EP 1 074 429 B1 discloses a light switch unit, in which a rotary switch and at least two pressure switches, which are arranged essentially diametrically with respect to the rotary switch, are provided in order to form a direct relationship between the spatial arrangement and the function of the switches.
DE 10 2007 063 420 A1 discloses a method for switching off assistance light functions of motor vehicles, such as, for example, the rain light and the freeway light, in which selected assistance light functions (such as, for example, the tunnel detection system and the dusk detection system) remain activated.
WO 2006/084536 A1 discloses a method for activating headlights of a motor vehicle, in which method a manual mode with manual activation of the headlights by means of a selector lever and an automatic mode for activating the headlights on the basis of an exterior lighting situation are provided, wherein in the automatic mode an override possibility is provided, with the result that the headlights can be changed into the corresponding lighting state by manual activation of the selector lever independently of the exterior lighting situation.